diff --git a/package.xml b/package.xml
index ec44bd1..519de58 100644
--- a/package.xml
+++ b/package.xml
@@ -87,6 +87,7 @@ Fixes
     <file role='test' name='cas_multi.phpt'/>
     <file role='test' name='check_if_persistent.phpt'/>
     <file role='test' name='check_if_pristine.phpt'/>
+    <file role='test' name='check_key.phpt'/>
     <file role='test' name='clone.phpt'/>
     <file role='test' name='compression_conditions.phpt'/>
     <file role='test' name='compression_types.phpt'/>
diff --git a/tests/check_key.phpt b/tests/check_key.phpt
new file mode 100644
index 0000000..74ec621
--- /dev/null
+++ b/tests/check_key.phpt
@@ -0,0 +1,132 @@
+--TEST--
+Memcached::checkKey()
+--SKIPIF--
+<?php include "skipif.inc";?>
+--FILE--
+<?php
+include dirname (__FILE__) . '/config.inc';
+$m = memc_get_instance (array (
+				Memcached::OPT_BINARY_PROTOCOL => false,
+				Memcached::OPT_VERIFY_KEY => true
+		));
+
+$keys = [
+	'foo',
+	'foo bar',
+	str_repeat('a',65),
+	str_repeat('b',250),
+	str_repeat('c',251),
+	'Montréal',
+	'København',
+	'Düsseldorf',
+	'Kraków',
+	'İstanbul',
+	'ﺎﺨﺘﺑﺍﺭ PHP',
+	'測試',
+	'Тестирование',
+	'پی ایچ پی کی جانچ ہو رہی ہے',
+	'Testataan PHP: tä',
+	'Að prófa PHP',
+	'د پی ایچ پی ازمول',
+	'Pruvà PHP'
+];
+foreach($keys as $key) {
+	echo "Checking \"$key\"" . PHP_EOL;
+	echo "MEMC_CHECK_KEY: ";
+	var_dump($m->checkKey($key));
+	echo "libmemcached: ";
+	var_dump($m->set($key, "this is a test"));
+    var_dump($m->getResultMessage());
+	echo "\n";
+}
+--EXPECT--
+Checking "foo"
+MEMC_CHECK_KEY: bool(true)
+libmemcached: bool(true)
+string(7) "SUCCESS"
+
+Checking "foo bar"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+MEMC_CHECK_KEY: bool(true)
+libmemcached: bool(true)
+string(7) "SUCCESS"
+
+Checking "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"
+MEMC_CHECK_KEY: bool(true)
+libmemcached: bool(true)
+string(7) "SUCCESS"
+
+Checking "ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "Montréal"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "København"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "Düsseldorf"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "Kraków"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "İstanbul"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "ﺎﺨﺘﺑﺍﺭ PHP"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "測試"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "Тестирование"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "پی ایچ پی کی جانچ ہو رہی ہے"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "Testataan PHP: tä"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "Að prófa PHP"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "د پی ایچ پی ازمول"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+
+Checking "Pruvà PHP"
+MEMC_CHECK_KEY: bool(false)
+libmemcached: bool(false)
+string(46) "A BAD KEY WAS PROVIDED/CHARACTERS OUT OF RANGE"
+